Re: Question on BOOT_CFLAGS vs. CFLAGS

[Mike Stump <mrs at apple dot com>]

On Dec 14, 2006, at 5:59 PM, Paul Brook wrote:
> On Friday 15 December 2006 01:37, Josh Conner wrote:
> > All -
> >
> > When I configure with --disable-bootstrap and build with:
> >
> >   CFLAGS="-g -O0"
> >
> > The resultant compiler is built with the specified options.   
> > However, if
> > I --enable-bootstrap, when I build with the same CFLAGS, these  
> > options
> > are not used to build the final compiler.  I can get past this by  
> > using
> > BOOT_CFLAGS="-g -O0", but that seems a bit inconsistent.
> >
> > My question is:  Is this behaving as designed or would it be  
> > reasonable
> > to file a bug and/or supply a patch to change the behavior so that
> > CFLAGS are respected whether bootstrapping is enabled or not?
>
> It is working as documented:
>
> http://gcc.gnu.org/onlinedocs/gccint/Makefile.html
> http://gcc.gnu.org/install/build.html

I read that, could you please quote the part that documents the  
current behavior.

Let me offer a counter quote:

If you want to save additional space during the bootstrap and in
the final installation as well, you can build the compiler binaries
without debugging information as in the following example.  This will  
save
roughly 40% of disk space both for the bootstrap and the final  
installation.
(Libraries will still contain debugging information.)

     make CFLAGS='-O' LIBCFLAGS='-g -O2' \
       LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap

I think that is pretty clear.

I think this is a bug that was unintentionally introduced by someone  
that didn't realize all the nuances of this.  If you examine the  
patch submission where this was changed, I don't recall they called  
out or discussed the changed behavior.  Do you have a pointer that  
shows otherwise?

Now, why do we do this, kinda simple, because this is a standard that  
trancends gcc and dates back a long, long time, see http:// 
www.gnu.org/prep/standards/standards.html for example.

The fix is simple, we just change BOOT_CFLAGS = -O2 -g to instead be $ 
(CFLAGS).  This way, if someone builds as documented in the manual,  
they get the results documented in the manual.